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<div class="titlepage"><div><div><h4 class="title">
<a name="asio.reference.basic_socket.async_wait"></a><a class="link" href="async_wait.html" title="basic_socket::async_wait">basic_socket::async_wait</a>
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<p>
          <a class="indexterm" name="asio.indexterm.basic_socket.async_wait"></a> 
Asynchronously
          wait for the socket to become ready to read, ready to write, or to have
          pending error conditions.
        </p>
<pre class="programlisting">template&lt;
    typename <a class="link" href="../WaitHandler.html" title="Wait handler requirements">WaitHandler</a>&gt;
<a class="link" href="../asynchronous_operations.html#asio.reference.asynchronous_operations.automatic_deduction_of_initiating_function_return_type"><span class="emphasis"><em>DEDUCED</em></span></a> async_wait(
    wait_type w,
    WaitHandler &amp;&amp; handler);
</pre>
<p>
          This function is used to perform an asynchronous wait for a socket to enter
          a ready to read, write or error condition state.
        </p>
<h6>
<a name="asio.reference.basic_socket.async_wait.h0"></a>
          <span><a name="asio.reference.basic_socket.async_wait.parameters"></a></span><a class="link" href="async_wait.html#asio.reference.basic_socket.async_wait.parameters">Parameters</a>
        </h6>
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<p class="title"><b></b></p>
<dl>
<dt><span class="term">w</span></dt>
<dd><p>
                Specifies the desired socket state.
              </p></dd>
<dt><span class="term">handler</span></dt>
<dd>
<p>
                The handler to be called when the wait operation completes. Copies
                will be made of the handler as required. The function signature of
                the handler must be:
</p>
<pre class="programlisting">void handler(
  const asio::error_code&amp; error // Result of operation
);
</pre>
<p>
                Regardless of whether the asynchronous operation completes immediately
                or not, the handler will not be invoked from within this function.
                Invocation of the handler will be performed in a manner equivalent
                to using <code class="computeroutput">asio::io_context::post()</code>.
              </p>
</dd>
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<h6>
<a name="asio.reference.basic_socket.async_wait.h1"></a>
          <span><a name="asio.reference.basic_socket.async_wait.example"></a></span><a class="link" href="async_wait.html#asio.reference.basic_socket.async_wait.example">Example</a>
        </h6>
<pre class="programlisting">void wait_handler(const asio::error_code&amp; error)
{
  if (!error)
  {
    // Wait succeeded.
  }
}

...

asio::ip::tcp::socket socket(io_context);
...
socket.async_wait(asio::ip::tcp::socket::wait_read, wait_handler);
</pre>
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<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2018 Christopher M. Kohlhoff<p>
        Distributed under the Boost Software License, Version 1.0. (See accompanying
        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
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